Previously, with AVIC, guest needs to disable x2APIC capability and
can only run in APIC mode to activate hardware-accelerated interrupt
virtualization. With x2AVIC, guest can run in x2APIC mode.
This feature is indicated by the CPUID Fn8000_000A EDX[14],
and it can be activated by setting bit 31 (enable AVIC) and
bit 30 (x2APIC mode) of VMCB offset 60h.
The mode of interrupt virtualization can dynamically change during runtime.
For example, when AVIC is enabled, the hypervisor currently keeps track of
the AVIC activation and set the VMCB bit 31 accordingly. With x2AVIC,
the guest OS can also switch between APIC and x2APIC modes during runtime.
The kvm_amd driver needs to also keep track and set the VMCB
bit 30 accordingly.
Besides, for x2AVIC, kvm_amd driver needs to disable interception for the
x2APIC MSR range to allow AVIC hardware to virtualize register accesses.
Testing:
* This series has been tested booting a Linux VM with x2APIC physical
and logical modes upto 511 vCPUs.
Regards,
Suravee
Suravee Suthikulpanit (13):
KVM: SVM: Add warning when encounter invalid APIC ID
x86/cpufeatures: Introduce x2AVIC CPUID bit
KVM: SVM: Detect X2APIC virtualization (x2AVIC) support
KVM: SVM: Only call vcpu_(un)blocking when AVIC is enabled.
KVM: SVM: Update max number of vCPUs supported for x2AVIC mode
KVM: SVM: Add logic to determine x2APIC mode
KVM: SVM: Update avic_kick_target_vcpus to support 32-bit APIC ID
KVM: SVM: Do not update logical APIC ID table when in x2APIC mode
KVM: SVM: Introduce helper function avic_get_apic_id
KVM: SVM: Adding support for configuring x2APIC MSRs interception
KVM: SVM: Add logic to switch between APIC and x2APIC virtualization
mode
KVM: SVM: Remove APICv inhibit reasone due to x2APIC
KVM: SVM: Use fastpath x2apic IPI emulation when #vmexit with x2AVIC
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/svm.h | 15 +-
arch/x86/kvm/svm/avic.c | 216 ++++++++++++++++++++++++++---
arch/x86/kvm/svm/svm.c | 102 ++++++++------
arch/x86/kvm/svm/svm.h | 13 +-
arch/x86/kvm/x86.c | 3 +-
arch/x86/kvm/x86.h | 1 +
7 files changed, 281 insertions(+), 70 deletions(-)
--
2.25.1
